<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
  <title>模块化</title>
  <link rel="stylesheet" href="css/layui.css">
</head>

<body>

  <script src="js/layui.js"></script>
  <script>
    //一般直接写在一个js文件中
    layui.use(['layer', 'form'], function () {
      var layer = layui.layer
        , form = layui.form;

      layer.msg('Hello World');
    });
  </script>
</body>

</html>